Nothing like a homemade ice pop on a hot day, all the more pleasant with a bit of alcohol.
In a small pan, heat the caster sugar and water, stirring to make the sugar dissolve.
Take the pan off the heat and add the mint leaves and stalks and the lime zest.
Cool the mixture and strain into a jug. Discard the mint and zest and mix in the lime juice and white rum.
Divide the cooled mixture among 10 x 75ml (3fl oz) ice pop molds. Don't worry if the mixture doesn't fill the molds completely, it's not supposed to.
Put the extra mint leaves into each mold.
Cover the mold with a lid and insert sticks. Leave the mold in the freezer until everything's solidified. To serve, remove the mold from the freezer and let sit for 10-15 minutes before removing the pops.